1.6.9 is the last version of Geiger Bot compatible with iOS 5. This was unexpected; however, the stability issues I encountered with Apple Maps in iOS 7 forced me to adopt Google Maps instead, which requires iOS 6 minimum.

iOS 4.3.1 Compatibility Information

1.6.9 is the last version of Geiger Bot compatible with iOS 4.3.1.

iOS 3.1.3 Compatibility Information

Unfortunately as of September 2012 Geiger Bot no longer works with:

iOS 3.1.3

ARMv6 architecture devices (ie, iPhone 1)

This is due to changes in the iOS development tools than were released with iOS 6. Prior to this point, to my knowledge, at least parts of Geiger Bot would run on even the oldest hardware.

iPad Differences

Generally speaking the iPad version is identical with some interface elements spread out to take advantage of the larger screen instead of having to navigating through screens. The main UI of the iPhone version is preserved in a HP28S-like virtual unit.